The goal of creating the expanded Human Oral Microbiome Database (eHOMD) is to provide the scientific community with comprehensive curated information o要 the bacterial species present in the human aerodigestive tract (ADT), which encompasses the upper digestive and upper respiratory tracts, including the oral cavity, pharynx, nasal passages, sinuses and esophagus.eHOMD should also serve well for the lower respiratory tract. Currently, eHOMD includes a total of 770 microbial species, 687 from version 14.51 of HOMD and 83 added in this expansion based o要 publicly available data o要 the microbiota of the aerodigestive tract outside of the mouth. Of all the species, 57% are officially named, 13% unnamed but cultivated and 30% are known o要ly as uncultivated phylotypes. O要e important aspect of theeHOMD, is that it presents a provisional naming scheme for the currently unnamed taxa, based o要 the 16S rRNA sequence phylogeny, so that strain, clone and probe data from any laboratory can be directly linked to a stably named reference scheme. TheeHOMD links sequence data with phenotypic, phylogenetic, clinical and bibliographic information. Genome sequences for aerodigestive tract bacteria determined as part of the HOMD project, the Human Microbiome Project and other sequencing projects are being added to the eHOMD as they become available. Genomes for 475 taxa (62% of all taxa, 85% of cultivated taxa) are currently available o要 eHOMD. The eHOMD site offers easy to use tools for viewing all publicly available ADT bacterial genomes. The curation of the HOMD Taxonomy Database is being carried out manually by experts in the oral research field.